Glider pickup apparatus



Jan. 6, 1948. I H. B. cowQLL, JR

d Dec. 6; 1943 Sheets-Sheet 1 I 4 ATTORNEYS.

Jan. 6, 1948. H. B. COWGILL, JR 2,433,893

I GLIDER PICK-UP APPARATUS Filed Dec. 6, 1943 s Sheets-Sheet 2 A TTORNE S.

1943. I H. B. COWGILL, JR 2,433,893

GLIDER PICK-UP APPARATUS Ill i Illi- INVENTOR;

. HarryBCow z'ZIQJz; BY d I ATTO EYS.

Patented Jan. 6, 1948 UNITED STATES a PATENT OFFICE 2.433.893 A p I GLIDER, PICKUP APPARATUS Harry B. ,Cowgill, Jr., Roekville Centre; N. Y. Application December 6, 1943, Serial No. 513,027

10 Claims. 1 v

This invention relates to apparatus useful as a means to facilitate picking up of gliders by a powered towing craft such as airplanes or dirigibles in flight.

The chief aim of my invention is to make possible the automatic coupling of a tow line from a glider at rest on the ground to the moving towing craft, and at the same time to bring the glider gradually up to speed before being actually" released for direct draft through the medium of the tow line by such towing craft.

Another object of my invention is to accomplish the foregoing without subsequent encumbrance of the towing craft or glider with auxiliaries other than the tow line itself. I

The above desiderata are realized in practice as hereinafter more fully disclosed through provision of a pick-up apparatus which includes'a reeling unit having two freely-rotative tapered intergeared drums. To the periphery of the small end of one of these drums is secured a cable whereof the free end is self-releasingly connected to a glider at rest at a distance rearward of the reeling unit as considered with respect to the direction of approach of the towing craft to which the glider is to be coupled with said cable slacked. n the other reel is wound a cable which is doubled upon itself and which has one of its ends only secured to the periphery of the drum at the small end of the latter. Positioned ahead of the reeling unit is a means for releasably supporting in horizontally open positions at an elevation, the free terminal loop of the doubled cable and a loop at the free end of the slacked tow line extending from the glider so that said loops can be en'- gaged by a pendent hook projection on the passing towing craft. Under the pull of the towing craft the doubled cable is unwound from its drum, while, through the intergearing, the other drum is incidentally rotated to progressively wind up the other cable, with attendant impartation of accelerating movement to the glider until it has acquired the speed of said towing craft. The first mentioned cable is automatically detached from the glider when said cable is substantially completely wound on its drum and as said glider passes over the reeling unit. This occurs concurrently with complete unwinding of the second cable from its drum with attendant automatic release thereof from the projection on the towing craft at a time when the slack of the tow line has been substantially taken up for pull of the glider thereafter directly by said towing craft.

.. tial engagement of the loops of the tow line and the doubled cable by the pendent projection of the flying towing craft.

Fig. 2 is a diagrammatic plan view of the reel- I ing unit'corresponding to Fig. 1.

Fig. 3 is a view looking as indicated by the angled arrows III-III in Fig. 1 showing the means for supporting the loops respectively of the tow line and the doubled cable.

Fig. 4 is a view like Fig. 1 showing conditions at thefend of the take-up operation with the cables detached respectively from the glider and the towing craft and with the glider directly connected to said towing craft.

Fig. 5 is a plan view ofthe reeling unit corresponding to Fig. 4,

} Fig. 6 is a view showing the reeling unit in top plan on a larger scale.

. Fig. 7 isa longitudinal sectional view of the reeling unittaken as indicated by the angled arrows VII -VII in Fig. 6.

. Fig. 8 is a cross sectional'view of the reeling unit taken as indicated by the angled arrows VIII-VIII in Figs. 6 and 7.

Fig. 9 is a fragmentary sectional view of the reeling unit taken as indicated by the angled arrows IX-IX in Figs. 6 and 7.

Fig. 10' is a fragmentary'view in longitudinal section showing the profile of one of the reel drums.

" Fig. 11.

In these illustrations the reel of my improved glider pick-up apparatus is generally designated by the numeral I5. As shown, its two drums l6 and I! are disposed alongside each other with their shafts l8 and I9 journaled in the side uprights 20 of a frame 2| anchored on the surface of a flat runway 22, the diameter of the small end of the drum I! being in this instance equal to the diameter of thelarge end of drum [6. The drum [6, it will be noted, has a curved tapering surface with a spiral groove 23 for reception of the cable 25 whereof one end is suitably secured to thesmall end of the drum, while its other end is vation above ground over the tops of a pair of 7 laterally-spaced standards 3| which are located somewhat forward of the reeling unit 15. The

drum ll is frusto-conical in configuration andhas a spiral groove 32 which is considerably deeper than that of the drum [6 for capacity to reeeive the cable 33 which is doubled upon itself as shownin Figs. 11 and 12, and, as shown in Figs. 1 and 3, wound on said drum with attendant formation of a free loop 34 which is adapted to' beplaced over the standards 3| with the loop 30pf the tow line 29. In order to confine the loop 34, a tape band of fabric is wrapped at B about the doubled cable. The end Qf the outer layer of the cable 33 is Se cured to the drum ll at the smallend of the latter by names 35, while the the of the inner layer is simply tucked in beneath the fixed enjd beset-a outer layer as further shown in Fig. 12. From Figs. 6 and '7 it will be noted that the drums I6 and I! are intergeared in simple, 'or one to one, ratio by chains 36 connecting sprocket wheels 31 and 38 at opposite ends of the drum shafts l8 and [9, said drums being thus arranged for simultaneous rotation at synchronous speeds. 4

For the purpose of insurin'g unifo'r'm winding of the" cable 25 on the drum I6 I have provided a; shifting fork 39 which is mounted on a; trans; verse screw spindle 40 journaled in bracket x: tensions 4| on the side uprights 20 of the d r'um frame 2|. By means of a sprocket chaifi 42lthe screw spindle 40 is driven from the shaft i8 of the drum l6; and through engagement of a pendent projection 390, on the shifting fork 39 with "2, guide rod 43 extendingc'iosswie between the bracket extensions 4|, said fork is restrained against rotation with said spindle. As best shown in Fig. 9, the thread on the spindle 4n terminates short of the inner sides of the braliet extensions 4| so that the follower 39 may leave the thread after'it has completed its tray erse in either direction to preclude jamming in cident to overrunning of the druml-B. The helical compression springs indicated at 45- in Fig: 9 cause the follower 39 to automatically re-engage the thread of the spindle 40 uponreversal in; the rotation of the latter after winding or unwind= ing of the cable 25. n e

In preparation for picking up of the glider 28, the cable 25 is completely unwound from thedrum [6 as shown in Figs. 1 and 2, pu lled-ta1ift, and its eye 26- engaged' with the hook 21 on said it the points q. Immediately upon this engage taped to the loop 34 of cable 33 at a few spaced points as indicated at C in Fig. 3. The towing craft, herein exemplified as a powered plane 46, is provided at the region of its gravity center with a pendent pick-up projection in the form of a hook 41 which is preferably arranged so that it may be retracted when not used for towing.

All being now in readiness,. the airplane 46 is next-n irdm rarward t the 'glider2 8 the piloted so that it's hook 41 will, in passing, engage the loops 30 and 34 of the tow lines 29 and the cable '33 supported horizontally open at the tops of the standards 3! as shown in Figs. 1 and 3, the engagement of both said loops being insured by virtue of their being lightly taped together at fnent, the pull on the cable 33 causes the drum H to rotate, which, by virtue of the sprocket chain connections 36, in turn causes rotation of the drum l6 and in turn winding of the cable to draw the glider 28; The drums l6 and I! are so proportioned and shaped as to determine uniform acceleration of the glider until it attains the speed of the plane 46, the cables 25 and 33 pulling oppositely as they move linearly with said drums rotatively at synchronous speeds. Duringthe picke up interval, the amount of the cable 33 drawn off at on revolution of the drums is eqfial to 1r X D (the dian'ietg-zr of the drum 1'!) glider. Through incidental rotation of the which, as before stated; isfixedly' clamped toth' littl drum. With this accomplished, the 34' of the cable 33 is' spread horizontally and en gagedover the tops of the standard 3|; PH ete- 1115011 the 16013 30 Of the t dw line- 2 a Sill'ilI'QIfI-S engaged over the tops of thes'tandards at with the excess length thereof to one side, and lightly over-running of the drums and the amount of the cable 25 taken up is equal to 1 d (the diameter of the drum l6). Thus as D and d gradually approach each other, the sp'fdof the 'glider increases until the cables reach the end portions of equal diameter of the drums l6 and I1, when the glider will have attaine'd the peed of the plan At the sta'ge last described, the slack of the tow line will be subst 'tiellly absorbed and the eye 26' at the free en 6; the cable 25 win drop off the hook 21 on the glider 28 as thelatter passes over the reeling unit [5. as shown n Fig. 4, the cable 33, by reason of ng its' loose endfreed from the druni II, reevih at the same time through the hook mat theme. as al sh wn n Fi 4, with; attendant rupture of the tape bands'B and e. The lengthof the tow line 29 is critical, it being made equal approximately to the doubled length of the eable 33. For all practical p'ur-f p'oses the speed of the plane 46 is kept constant duri 'g the picliu'p. The tendency of the mane t6 slow down at the time of initial engagement of its hook with thlo'ops of the tow lin e"29 and the cable as shat-11a be cempensated by the 015th: mg of the throttle of the plane motor by the pilot.- The pick up is thus "effected substantially without impartation of abrupt strains either to the glider or the plane. In practice a suitable brake means is provided to prevent excessive i6 and I1. Such brake means may be of any approved type and for this reason illustration thereof has been omitted from the drawings. For the purposes of re-windin'g, I may provide a crank handle for application to either of the drum shafts.

liaving' thus described my invention, I claim: 1; Glider pick-up apparatus including a stand ard adapted toreleas'ably support at an elevation the free end of a tow line extending forwardly frorn a glider positioned at rest on the dgan auxiliary cable adapted to be cona't one eridto the front of the glider; a tame adapted to have one of its ends releases-1y supported by thef stan dard so that it "and the free end of the tow linecan be" picked up by a catch projection on a passing towing craft in flight; a reeling unit rearward of the standard operated through pull on the second cable by the towing craft including means to' gradually take up the first cable and impart accelerated movement to the glider until it attains the speed of the towing craft, and means automatically operative to effect release of the cables respectively when the speed of the glider is substantially equal to that of the towing craft for draft thereafter by said tow line.

2. Glider pick-up apparatus according to claim 1, in which the reeling unit comprises tapered drum means whereto the first mentioned cable is connected to the small end of said means so as to wind toward the large end of the latter during the pick up, and in which the second cable is wound upon the drum means so as to unwind toward the small end of the latter during the pick up.

3. Glider pick-up apparatus according to claim 1, in which the reeling unit comprises a pair of intergeared tapered drums; in which the first mentioned cable is connected to the periphery of one of said drums at the small end so as to wind toward the large end of said drum during the pick up; and in which the second cable is wound upon the other drum so as to unwind from the large end of the latter toward the smal1 end during the pick up.

4. Glider pick-up apparatus according to claim 1, in which the reeling unit comprises a pair of intergeared tapered drums; in which the first mentioned cable is connected to the periphery of one of said drums at the small end so as to wind toward the large end of said drum during the pick up; and in which the second cable is wound upon the other drum so as to unwind from the large end of the latter toward the small end during the pick up; and in which the diameter of the small end of the last mentioned drum is equal to the diameter of the large end of the first mentioned drum.

5. Glider pick up apparatus according to claim 1, in which the reeling unit comprises a pair of intergeared tapered drums; in which the first mentioned cable is connected to the periphery of one of said drums at the small end so as to wind toward the large end of said drum during the pick up; in which the second cable is wound upon the other drum so as to unwind from the large end of the latter toward the small end during the pick up; in which the taper of the last mentioned drum is straight; in which the taper of the first drum is curved; and in which the diameter of the small end of said other drum is equal to the diameter of the large end of the first drum.

6. Glider pick-up apparatus according to claim 1, further including a bearing frame in which the reeling unit includes drums which are journaled in juxtaposed relation; and means by which said drums are intergeared comprising sprockets on their respective axes, and a chain connecting said sprockets.

7. Glider pick-up apparatus according to claim 1, further including supporting frame having side standards with bearings in which the reeling unit includes drums which are journaled in juxtaposed relation, a traversing guide for the first cable; a crosswise screw spindle engaging the traversing guide and also journaled in the side standards of the bearing frame and driven from one of the drum axes, the thread of said spindle terminating short of said standards to permit the guide to run off after completion of its travel in either direction; and compression springs at the insides of said standards to cause the guide to automatically re-engage the thread upon subsequent reversal of said spindle.

8. Glider pick-up apparatus according to claim 1, in which the reeling unit comprises tapered drum means whereto the first cable is fixedly connected to the periphery at the small end; and

whereto one end of the second cableis fixedly connected to the periphery of said drum means at the large end; in which said second cable is wound double in readiness for the pick-up operation upon the drum means with its other end tucked beneath the fixed end so that a loop is formed for engagement by the catch projection on the towing craft, capable of freeing itself from said projection after complete unreeling of said second cable.

9. Pick-up apparatus of th character described including a pair of cables; and a reeling unit comprising an accelerating drum with a varying taper to the small end of which one of the cables is connected so as to wind toward the larger end of the drum; a driving drum with a uniform taper to the larger end of which the other cable is connected so as to unwind toward the smaller end during the pick-up; and gearing connecting the drums for rotation together.

10. Pick-up apparatus according to claim 9, in which the diameter of the small end of the driving drum is equal in diameter to the large end of the accelerating drum so that the linear speeds of the two cables will be the same at the end of the pick-up operation.

HARRY B. COWGILL, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 599,769 Crosby Mar. 1, 1898 1,415,847 Sperry May 9, 1922 539,995 Nason May 28, 1895 

